1. Field of the Invention
The present invention generally relates to a fingerprint identification system, and more particularly to a fingerprint identification chip with enhanced electrostatic discharge (ESD) protection.
2. Description of Related Art
Fingerprint identification has been gradually used in electronic devices, particularly handheld electronic devices (e.g., mobile phones or tablet personal computers) to replace password identification in a more convenient and safer manner.
Static electricity of human body or machine into a chip may generate large transient current that damages the chip. Electrostatic discharge (ESD) protection is thus an essential and important function for the chips. As the surface of a fingerprint identification chip is frequently subjected to finger touch, it thus needs more ESD protection capability than a general integrate circuit chip to ensure normal operation of the fingerprint identification.
However, the ESD protection circuit of conventional fingerprint identification chips is usually too late to be activated, such that static electricity may enter, malfunction or even damage internal circuitry of the chips. Moreover, the ESD protection circuit of conventional fingerprint identification chips is ordinarily not strong enough, such that large electrostatic discharge may cause breakdown to the ESD protection circuit and deprive the internal circuitry of ESD protection.
Accordingly, a need has arisen to propose a novel fingerprint identification chip with enhanced ESD protection to improve disadvantages of the conventional fingerprint identification chips.